As an energy carrier characterized by its high energy density and eco-friendliness, hydrogen holds a pivotal position in energy transition. This paper elaborates on the scientific foundations and recent progress of photo- and electro-catalytic water splitting, including the corresponding mechanism, material design and optimization, and the economy of hydrogen production. It systematically reviews the research progress in photo(electro)catalytic materials, including oxides, sulfides, nitrides, noble metals, non-noble metal, and some novel photocatalysts and provides an in-depth analysis of strategies for optimizing these materials through material design, component adjustment, and surface modification. In particular, it is pointed out that nanostructure regulation, dimensional engineering, defect introduction, doping, alloying, and surface functionalization can remarkably improve the catalyst performance. The importance of adjusting reaction conditions, such as pH and the addition of sacrificial agents, to boost catalytic efficiency is also discussed, along with a comparison of the cost-effectiveness of different hydrogen production technologies. Despite the significant scientific advancements made in photo(electro)catalytic water splitting technology, this paper also highlights the challenges faced by this field, including the development of more efficient and stable photo(electro)catalysts, the improvement of system energy conversion efficiency, cost reduction, the promotion of technology industrialization, and addressing environmental issues.

To enhance the therapeutic efficacy of postoperative colorectal cancer treatment and prevent peritoneal metastasis, we propose a strategy utilizing the photothermal-induced ultra-efficient and long-lasting multi-stage immuno-chemo synergistic therapy. To implement this strategy, oxaliplatin (OXA), curcumin (Cur), and Mn²⁺ were coordinated to form infinite coordination polymer nanoparticles (OXA–Mn(II)–Cur ICP NPs). These nanoparticles are encapsulated with polydopamine (PDA) to create OXA–Mn(II)–Cur ICP@PDA NPs, which are subsequently embedded in a sprayable hyaluronic acid-based hydrogel. The resulting ICP@PDA NPs@composite hydrogel exhibits strong tissue adhesion and segmented pH-responsive drug release properties. Notably, the hydrogel can sustainably release drugs for over 20 days in vivo, maximizing local drug concentration while minimizing systemic toxic side effects. Each component of the composite hydrogel serves multiple functions, and its application to postoperative tumor sites enables long-term, dual-pathway, multi-stage immune activation. This immune response synergizes with chemotherapy to achieve a highly effective therapeutic outcome. In vivo experiments demonstrated that the composite hydrogel effectively eliminates residual tumors, ensuring a 100% survival rate without recurrence for 80 days in treated mice. Furthermore, it inhibits peritoneal metastasis and completely eradicates intraperitoneal tumors within 20 days. The ICP@PDA NPs@composite hydrogel represents a promising therapeutic platform for postoperative colorectal cancer treatment and metastasis prevention.